
#include <stdlib.h>
#include <stdio.h>
#include <jni.h>
#include <assert.h>

#include <termios.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <jni.h>
#include <strings.h>
#include "so_laodao_serialport_SerialPort.h"


#include "android/log.h"

static const char *TAG = "serial_port";
#define LOGI(fmt, args...) __android_log_print(ANDROID_LOG_INFO,  TAG, fmt, ##args)
#define LOGD(fmt, args...) __android_log_print(ANDROID_LOG_DEBUG, TAG, fmt, ##args)
#define LOGE(fmt, args...) __android_log_print(ANDROID_LOG_ERROR, TAG, fmt, ##args)


static speed_t getBaudrate(jint baudrate) {
    switch (baudrate) {
        case 0:
            return B0;
        case 50:
            return B50;
        case 75:
            return B75;
        case 110:
            return B110;
        case 134:
            return B134;
        case 150:
            return B150;
        case 200:
            return B200;
        case 300:
            return B300;
        case 600:
            return B600;
        case 1200:
            return B1200;
        case 1800:
            return B1800;
        case 2400:
            return B2400;
        case 4800:
            return B4800;
        case 9600:
            return B9600;
        case 19200:
            return B19200;
        case 38400:
            return B38400;
        case 57600:
            return B57600;
        case 115200:
            return B115200;
        case 230400:
            return B230400;
        case 460800:
            return B460800;
        case 500000:
            return B500000;
        case 576000:
            return B576000;
        case 921600:
            return B921600;
        case 1000000:
            return B1000000;
        case 1152000:
            return B1152000;
        case 1500000:
            return B1500000;
        case 2000000:
            return B2000000;
        case 2500000:
            return B2500000;
        case 3000000:
            return B3000000;
        case 3500000:
            return B3500000;
        case 4000000:
            return B4000000;
        default:
            return -1;
    }
}





/*
 * 设置串口数据，校验位,速率，停止位
 * @param nBits 类型 int数据位 取值 位7或8
 * @param nEvent 类型 char 校验类型 取值N ,E, O,,S
 * @param mStop 类型 int 停止位 取值1 或者 2
 */
int fd;

int set_opt(jint nBits, jchar nEvent, jint nStop) {

    LOGE("set_opt:nBits=%d,nEvent=%c,nSpeed=%d,nStop=%d", nBits, nEvent, nStop);


    struct termios newtio;

    if (tcgetattr(fd, &newtio) != 0) {

        LOGE("setup serial failure");

        return -1;

    }

    bzero(&newtio, sizeof(newtio));

    //c_cflag标志可以定义CLOCAL和CREAD，这将确保该程序不被其他端口控制和信号干扰，同时串口驱动将读取进入的数据。CLOCAL和CREAD通常总是被是能的

    newtio.c_cflag |= CLOCAL | CREAD;


    switch (nBits) //设置数据位数
    {

        case 7:

            newtio.c_cflag &= ~CSIZE;

            newtio.c_cflag |= CS7;

            break;

        case 8:

            newtio.c_cflag &= ~CSIZE;

            newtio.c_cflag |= CS8;

            break;

        default:


            break;

    }

    switch (nEvent) //设置校验位
    {

        case 'O':

            newtio.c_cflag |= PARENB; //enable parity checking

            newtio.c_cflag |= PARODD; //奇校验位

            newtio.c_iflag |= (INPCK | ISTRIP);


            break;

        case 'E':

            newtio.c_cflag |= PARENB; //

            newtio.c_cflag &= ~PARODD; //偶校验位

            newtio.c_iflag |= (INPCK | ISTRIP);


            break;

        case 'N':

            newtio.c_cflag &= ~PARENB; //清除校验位



            break;


        default:


            break;

    }
    switch (nStop) //设置停止位
    {

        case 1:

            newtio.c_cflag &= ~CSTOPB;

            break;

        case 2:

            newtio.c_cflag |= CSTOPB;

            break;

        default:

            // LOGW("nStop:%d,invalid param", nStop);

            break;

    }

    newtio.c_cc[VTIME] = 0;//设置等待时间

    newtio.c_cc[VMIN] = 0;//设置最小接收字符

    tcflush(fd, TCIFLUSH);

    if (tcsetattr(fd, TCSANOW, &newtio) != 0) {

        LOGE("options set error");

        return -1;

    }


    LOGE("options set success");
    return 1;

}





/*
 * Class:     android_serialport_SerialPort
 * Method:    open
 * Signature: (Ljava/lang/String;II)Ljava/io/FileDescriptor;
 */
JNIEXPORT jobject JNICALL Java_so_laodao_serialport_SerialPort_open
        (JNIEnv *env, jclass thiz, jstring path, jint baudrate, jint flags) {
    int fd;
    speed_t speed;
    jobject mFileDescriptor;

    /* Check arguments */
    {
        speed = getBaudrate(baudrate);
        if (speed == -1) {
            /* TODO: throw an exception */
            LOGE("Invalid baudrate");
            return NULL;
        }
    }

    /* Opening device */
    {
        jboolean iscopy;
        const char *path_utf = (*env)->GetStringUTFChars(env, path, &iscopy);
        LOGD("Opening serial port %s with flags 0x%x", path_utf, O_RDWR | flags);
        fd = open(path_utf, O_RDWR | flags);
        LOGD("open() fd = %d", fd);
        (*env)->ReleaseStringUTFChars(env, path, path_utf);
        if (fd == -1) {
            /* Throw an exception */
            LOGE("Cannot open port");
            /* TODO: throw an exception */
            return NULL;
        }
    }

    /* Configure device */
    {
        struct termios cfg;
        LOGD("Configuring serial port");
        if (tcgetattr(fd, &cfg)) {
            LOGE("tcgetattr() failed");
            close(fd);
            /* TODO: throw an exception */
            return NULL;
        }

        cfmakeraw(&cfg);
        cfsetispeed(&cfg, speed);
        cfsetospeed(&cfg, speed);

        if (tcsetattr(fd, TCSANOW, &cfg)) {
            LOGE("tcsetattr() failed");
            close(fd);
            /* TODO: throw an exception */
            return NULL;
        }

        /*这是查阅相关博客(https://www.cnblogs.com/rui1236/p/5988074.html)自己添加的方法，
         * 可以设置 校验位，停止位等等，一般都是默认 8, 'N', 1。不配置该方法，经过测试也是没问题的*/
        /*配置校验位 停止位等等 dataBits 数据位 ; stopBits 停止位 ; parity  校验位 ;baudrate 波特率*/
       /* set_opt(databits, parity, stopbits);*/
        //set_opt(8, 'N', 1);

    }

    /* Create a corresponding file descriptor */
    {
        jclass cFileDescriptor = (*env)->FindClass(env, "java/io/FileDescriptor");
        jmethodID iFileDescriptor = (*env)->GetMethodID(env, cFileDescriptor, "<init>", "()V");
        jfieldID descriptorID = (*env)->GetFieldID(env, cFileDescriptor, "descriptor", "I");
        mFileDescriptor = (*env)->NewObject(env, cFileDescriptor, iFileDescriptor);
        (*env)->SetIntField(env, mFileDescriptor, descriptorID, (jint) fd);
    }

    return mFileDescriptor;
}







/*
 * Class:     cedric_serial_SerialPort
 * Method:    close
 * Signature: ()V
 */
JNIEXPORT void JNICALL Java_so_laodao_serialport_SerialPort_close
        (JNIEnv *env, jobject thiz) {
    jclass SerialPortClass = (*env)->GetObjectClass(env, thiz);
    jclass FileDescriptorClass = (*env)->FindClass(env, "java/io/FileDescriptor");

    jfieldID mFdID = (*env)->GetFieldID(env, SerialPortClass, "mFd", "Ljava/io/FileDescriptor;");
    jfieldID descriptorID = (*env)->GetFieldID(env, FileDescriptorClass, "descriptor", "I");

    jobject mFd = (*env)->GetObjectField(env, thiz, mFdID);
    jint descriptor = (*env)->GetIntField(env, mFd, descriptorID);

    LOGD("close(fd = %d)", descriptor);
    close(descriptor);
}
